The contact device is incorporated, for example, in a rotation sensor adapted to sense a rotational position of a rotating body. The rotation sensor makes a movable contact of the contact device slide on a resistive body in response to the rotation of the rotating body, detects a value of resistance between an end of the resistive body and the movable contact, and thus determines the rotational position of the rotating body.
As a known example of the contact device of this kind, a conventional contact device 1 is illustrated in FIGS. 4 and 5. As shown in these figures, the contact device 1 includes an electrically-conductive movable contact 2 made by a pressed metal sheet, and a holder 3 made of electrical-insulating resin and adapted to hold the movable contact 2. The movable contact 2 includes a plate-like contact base 21 and a contact body 22 obliquely upstanding from an end of the contact base 21.
A distal end of the contact base 21 (“distal” or “proximal” being defined with reference to the contact body 22) is bent downward by 90 degrees relative to a plane from which the contact bodies upstand, the distal end defining a 90-degrees-bent fixing portion 23. The fixing portion 23 includes a pair of raised portions 23a made by press working, and a resilient piece 23b made by cutting and raising a region of the fixing portion 23 between the raised portions 23a. The contact body 22 includes at its tip a contacting portion 22a made in a convex shape by press working. The contacting portion 22a is adapted to be slid on the resistive body.
The holder 3 shown in FIG. 5 includes a vertical hole 36 into which the fixing portion 23 of the movable contact 2 is inserted. When the fixing portion 23 of the movable contact 2 is inserted into the vertical hole 36, the pair of raised portions 23a provided on the fixing portion 23 is press-fit into the vertical hole 36, and the resilient piece 23b provided on the fixing portion 23 biases the inner wall of the vertical hole 36. Thus, the movable contact 2 is secured and prevented from being detached from the holder 3.